Xing is a Monarchy, whose monarch holds the title of Emperor. It's composed by fifty hereditary clans all under the rule of a single Emperor, who cements his rule by taking the daughter of each clan's chief to be his concubine and bear him a single heir for each clan.
While this method works to ensure fealty to the Emperor by binding each clan to him by blood through their ruling families, it creates a great deal of contention between the clans as all the heirs compete to inherit the throne. As it stands, it is common for the various heirs and their vassals to make assassination attempts against their royal siblings in order to clear the playing field.
As of 1914, there are forty-three heirs (twenty-four princes and nineteen princesses) competing savagely to ascend to the throne held by their father, who is reported to be in failing health.
Little is known about the geography of Xing itself, but it is known by its connection to Amestris through a vast and treacherous desert, which represents a great challenge for those with plans to cross it. The desert has been a major reason for the lack of relations with Amestris. Relations with its eastern neighbors are currently unknown.While rare, it isn't impossible for travelers from Xing to undertake the harrowing venture to the west. There is talk of a sea route by which immigrants or visitors may reach nations such as Amestris, but the shortest and most direct route is across the perilous desert. Through these routes, there exists a sizable merchant system used to transport literature, weapons and people across, legally or otherwise.
As of the end of the series, it is said General Roy Mustang has made a pact with Emperor Ling Yao to build a railroad from Ishval all the way to Xingese border, inaugurating a trade route.
At the end of the 2009 anime, Xing is shown on a map and it seems to be the largest known country. However, Drachma may be larger.
Of the fifty clans only three have been named in the course of the series - the Yao clan (from which Ling, Lan Fan and Fu come), the Chang clan (from which May and Xiao-Mei come) and the Han clan (a man from this clan leads Edward, Breda and Armstrong to the ruins of Xerxes). The fifty clans all make up the population, though their sizes can vary. The Chang clan is said to be small with little power, while the Yao clan is stated to have over 500,000 people.
Separated from the cluster of western nations by expansive, sandy badlands, Xing's culture and customs vary rather greatly from those in Amestris and its border countries and little information passes freely across the harsh, barren divide in either direction. Warriors of Xing, rather than relying on traditional western means of combat, have developed their own style of martial arts which blends acrobatic skills with melee weapon combat. Additionally, Xingese martial artists appear capable of greatly heightened senses such as sight and hearing as well as the development of a sixth sense that allows them to detect and appraise the presence and flow of life energy as it exists within human souls.
While there is enough to suggest that Xing is not far behind Amestris in terms of technological advancement, common Amestrian practices such as automail limbs are but stories within the empire. However, Xing's own arsenal of specialized grenades is rather impressive, boasting explosive types unknown in Amestris, such as capsicum tear gas grenades and flashbombs.
- Main article: Alkahestry
Another of Xing's unique customs is the practice of the Alkahestry, an alternate type of alchemy. Whereas Amestrian Alchemy claims to have its roots in the energy of tectonic shifts and practices manipulation of matter toward scientifically practical ends as well as a means to military supremacy, Alkahestry operates on the concept of fashioning elixirs and, therefore, is focused on mainly medicinal purposes. The basic principle of Alkahestry is centered on a concept called the "Dragon's Pulse" which speaks of the earth itself having a constant flow of chi (life energy) which flows from the tops of mountains down to the land, nourishing everything it passes with that energy as does blood coursing through the veins. Using this concept, Alkahestrists are capable of a higher level of medical transmutation than Amestrian alchemists - transmitting chi through the pathways of the human body to cure mild ailments as well as minor injuries - and can even project their transmutations over long distances and wide areas by accessing and guiding that current to their own means.
Four hundred years ago, the practices which would give rise to this Xingese alchemy could not be truly called "alchemy" at all, but a series of misguided attempts at mystical healing through the ingestion of various substances. In fact, it is said that three whole generations of the imperial family died from ingesting mercury because they believed that it promoted longevity. It wasn't until a mysterious figure they call "The Philosopher of the West", who had supposedly come from Xerxes, appeared in Xing with his alchemical teachings that Xingese Alkahestry was born - created from a melding of the new teachings and the old metaphysical healing practices.
Of all countries mentioned in the series, Xing seems to be the most isolated one, both due to its geographical position and its state's regime.
While that might be regarded as a down side, it had also prevented Xing from any disputes it might have with the expanding country of Amestris, being the only neighboring country that doesn't have any records of confrontation with them. Up to the year of 1915, the relations between Xing and Amestris seem to be limited to the black market of merchandise and people.
As Führer Grumman rose to power and the Amestrian Foreign Policy changed drastically, the two countries began to have a closer connection, the strengthening of economic and technical agreements between Amestris and Xing being an emblematic symbol of Amestris' policy' shift. The inauguration of the trade route between the countries became a mark on their foreign relations history.
- Xing can be considered the equivalent of China in the world of Fullmetal Alchemist, as people are very skilled in martial arts and have invented portable explosives. In addition, the word "xing" means "star" in Mandarin Chinese, which may be a play on the future emperor Ling's name meaning "dawn".
- Xing's medicine-based Alkahestry parallels China's early alchemic studies. The Chinese sought after the secrets behind alchemy strictly for healing purposes. And like what happened to Xingese rulers before the coming of the Sage of the West, Chinese emperors who were obsessed with extending their lives with dubious alchemic elixirs ended up dying to the toxic effects of the components, which usually included mercury amongst other ingredients.
- In addition to the heavy parallels to China, Xing has some smaller aspects of their culture appear to be Japan-inspired as well, such as the obviously ninja-based skills, weaponry, and clothing Fu and Lan Fan sport, as well as Ling's use of the strips of cotton cloth known as "sarashi" that were historically worn by Samurai and other Japanese peoples under their clothes. Ling's signature yellow shirt is also worn in a manner that is similar to the Japanese Happi coat.